Alert archive / Pennsylvania / Mesoscale Discussions in 2011
Mesoscale Discussion 994
The Storm Prediction Center issued this mesoscale discussion at May 27, 2011, 12:24 PM EDT for 7 states. It was in force for 96 min.
The area
The outline as issued.
The facts
- Issued
- May 27, 2011, 12:24 PM EDT (16:24 UTC)
- Expired
- May 27, 2011, 2:00 PM EDT
- In force
- 96 min
- Issued by
- the Storm Prediction Center
All 88 counties
Berkshire County, MA, Baltimore County, MD, Carroll County, MD, City of Baltimore, MD, Frederick County, MD, Howard County, MD, Montgomery County, MD, Prince George's County, MD, Washington County, MD, Sussex County, NJ, Albany County, NY, Broome County, NY, Chenango County, NY, Columbia County, NY, Delaware County, NY, Greene County, NY, Montgomery County, NY, Otsego County, NY, Rensselaer County, NY, Saratoga County, NY, Schenectady County, NY, Schoharie County, NY, Sullivan County, NY, Ulster County, NY, Adams County, PA, Berks County, PA, Bradford County, PA, Carbon County, PA, Columbia County, PA, Cumberland County, PA, Dauphin County, PA, Franklin County, PA, Fulton County, PA, Juniata County, PA, Lackawanna County, PA, Lancaster County, PA, Lebanon County, PA, Lehigh County, PA, Luzerne County, PA, Lycoming County, PA, Mifflin County, PA, Monroe County, PA, Montour County, PA, Northampton County, PA, Northumberland County, PA, Perry County, PA, Pike County, PA, Schuylkill County, PA, Snyder County, PA, Sullivan County, PA, Susquehanna County, PA, Union County, PA, Wayne County, PA, Wyoming County, PA, York County, PA, Arlington County, VA, Caroline County, VA, City of Alexandria, VA, City of Charlottesville, VA, City of Fairfax, VA, City of Falls Church, VA, City of Fredericksburg, VA, City of Manassas, VA, City of Manassas Park, VA, City of Winchester, VA, Clarke County, VA, Culpeper County, VA, Fairfax County, VA, Fauquier County, VA, Fluvanna County, VA, Frederick County, VA, Goochland County, VA, Greene County, VA, King George County, VA, Loudoun County, VA, Louisa County, VA, Madison County, VA, Orange County, VA, Page County, VA, Prince William County, VA, Rappahannock County, VA, Shenandoah County, VA, Spotsylvania County, VA, Stafford County, VA, Warren County, VA, Berkeley County, WV, Jefferson County, WV, Morgan County, WV
The radar
The Philadelphia radar (KDIX), 146 km from the middle of the area, began a volume at 16:24 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
The watches that followed
Watches SPC issued over any of the same counties within four hours of this discussion.
The nearest sounding before it
Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 4.4 hours before the alert went out and 109 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 95 J/kg
- Mixed-layer CIN
- -299 J/kg
- Mixed-layer LCL
- 1125 m above ground
- 0-6 km bulk shear
- 44 kt
- 0-1 km storm-relative helicity
- -15 m²/s²
- 0-3 km storm-relative helicity
- 20 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.2
The text
As transmitted, in the capitals the NWS used until 2016.
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</html>SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 27, 12:57 PM EDT | Severe Thunderstorm Watch | SPC | Allegany, Anne Arundel, Baltimore, Calvert, Carroll, Charles and 8 more | 9 hr |
| May 27, 3:29 PM EDT | Mesoscale Discussion | SPC | Saint Mary's | 91 min |
| May 27, 6:14 PM EDT | Mesoscale Discussion | SPC | Anne Arundel, Baltimore, Carroll, Cecil, Charles, Frederick and 7 more | 2 hr |
| May 27, 1:18 PM EDT | Mesoscale Discussion | SPC | Franklin | 87 min |
| May 27, 2:00 PM EDT | Severe Thunderstorm Watch | SPC | Berkshire, Franklin, Hampden, Hampshire | 6 hr |
| May 27, 5:49 PM EDT | Mesoscale Discussion | SPC | Berkshire, Franklin | 56 min |
| May 26, 8:54 PM EDT | Mesoscale Discussion | SPC | Adams, Berks, Bradford, Carbon, Columbia, Cumberland and 21 more | 66 min |
| May 26, 11:22 PM EDT | Mesoscale Discussion | SPC | Albemarle, Amherst, Appomattox, Augusta, Bedford, Buckingham and 18 more | 113 min |
| May 27, 11:26 AM EDT | Mesoscale Discussion | SPC | Brunswick, Dinwiddie, Greensville, Lunenburg, Mecklenburg, Nottoway and 1 more | 94 min |
| May 27, 12:06 PM EDT | Severe Thunderstorm Watch | SPC | Amelia, Amherst, Appomattox, Bedford, Botetourt, Brunswick and 52 more | 7 hr |
| May 27, 6:24 PM EDT | Mesoscale Discussion | SPC | Albemarle, Amelia, Amherst, Appomattox, Bedford, Brunswick and 43 more | 66 min |
Nearby
Mesoscale Discussions in Pennsylvania, 2011Mesoscale Discussions in Virginia, 2011Mesoscale Discussions in New York, 2011Every mesoscale discussion in 2011
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.